Coated paperboard

Abstract

The present disclosure provides a coated paperboard comprising a paperboard substrate and a coating layer wherein: the coating layer comprises a pigment mixture and a binder in a dry weight ratio within the range of from 100:14 to 100:25; the pigment mixture comprises a calcium carbonate pigment and a clay pigment in a dry weight ratio within the range of from 98:2 to 92:8; and the calcium carbonate pigment has a particle size distribution (wt. %<2 μm) within the range of from 75 to 95.

1 . A coated paperboard comprising a paperboard substrate and a coating layer wherein:
 the coating layer comprises a pigment mixture and a binder in a dry weight ratio within the range of from 100:14 to 100:25;   the pigment mixture comprises a calcium carbonate pigment and a clay pigment in a dry weight ratio within the range of from 98:2 to 92:8; and   the calcium carbonate pigment has a particle size distribution (wt. %<2 μm) within the range of from 75 to 95.   
     
     
         2 . The coated paperboard according to  claim 1 , wherein the calcium carbonate pigment and the clay pigment comprise 100 wt. % of the pigment mixture. 
     
     
         3 . The coated paperboard according to  claim 1  wherein the binder is a styrene-acrylic copolymer or styrene-butadiene copolymer. 
     
     
         4 . The coated paperboard according to  claim 1 , wherein the binder is a starch-based binder. 
     
     
         5 . The coated paperboard according to  claim 1 , wherein the coating layer further comprises a co-binder. 
     
     
         6 . The coated paperboard according to  claim 1 , wherein the calcium carbonate pigment is ground calcium carbonate. 
     
     
         7 . The coated paperboard according to  claim 1 , wherein the coat weight of the coating layer is 5-16 g/m 2 . 
     
     
         8 . The coated paperboard according to  claim 1 , wherein the coated paperboard comprises a pre-coating arranged between the paperboard substrate and the coating layer. 
     
     
         9 . The coated paperboard according to  claim 8 , wherein the pre-coating comprises binder and pigment. 
     
     
         10 . The coated paperboard according to  claim 8 , wherein the coat weight of the pre-coating and the coating layer together is 10-18 g/m 2 . 
     
     
         11 . The coated paperboard according to  claim 1 , wherein the coated paperboard has a Parker Print Surf roughness of 3.2 μm or less, as measured according to ISO 8791-4. 
     
     
         12 . The coated paperboard according to  claim 1 , wherein the coated paperboard has a Bendtsen roughness of 250 ml/min or less, as measured according to ISO 8791-2. 
     
     
         13 . The coated paperboard according to  claim 1  to  any one of the preceding claims , which is a liquid packaging board (LPB). 
     
     
         14 . The coated paperboard according to  claim 13 , wherein the paperboard substrate comprises at least two plies. 
     
     
         15 . The coated paperboard according to  claim 14 , wherein each of the plies comprise hydrophobic size. 
     
     
         16 . The coated paperboard according to  claim 15 , wherein each of the plies of the paperboard substrate comprises at least 1.5 kg/ton fiber of hydrophobic size. 
     
     
         17 . The coated paperboard according to  claim 5 , wherein the co-binder is polyvinyl alcohol, carboxymethyl cellulose and/or starch. 
     
     
         18 . The coated paperboard according to  claim 9 , wherein the pre-coating comprises coarser pigments than the coating layer. 
     
     
         19 . The coated paperboard according to  claim 14 , wherein the paperboard substrate comprises three plies. 
     
     
         20 . The coated paperboard according to  claim 15 , wherein the hydrophobic size is alkenyl succinic anhydride (ASA), alkyl ketene dimer (AKD) and/or rosin size.